In the recovery of oil from a subterranean formation, primary recovery methods utilizing the natural formation pressure to produce the oil typically allow recovery of only a portion of the oil contained within the formation. Additional oil and hydrocarbon compounds from the formation may be produced by improved oil recovery (e.g. water injection) or enhanced oil recovery (EOR) methods.
Typically, water used in improved oil recovery and/or enhanced oil recovery production operations must be processed. Processing the source water generally includes filtering the water to remove solid particles and removing dissolved solids. Nanofiltration, Ultrafiltration, and/or Reverse Osmosis membranes can be used in this filtration process. The membrane filtration process usually generates a filtered water stream containing a reduced amount of dissolved solids, and often generates a rejection stream with a more concentrated amount of dissolved solids than the pre-filtered water.
The resulting rejection stream must be directed somewhere. In the case of oil production operations in the ocean, the rejection stream can usually be safely outlet back into the ocean. However, there are some seawater environments in which the rejection stream cannot be sent back to the source water environment, either for environmental, regulatory, or some other reason. In addition, injection operations occurring on land or where a natural sink for the rejection stream is not present, the rejection stream must typically be directed to a reject water storage, be further processed, and/or be hauled offsite from the production operation. It is desirable to find a way to use or dispose of the rejection water produced by water processing more efficiently.
While embodiments of this disclosure have been depicted and described and are defined by reference to exemplary embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.